Ductless filtration systems for robotics instruments can be custom engineered for specific fume/particle or containment problems. Modular design enables building to specification economically. Positive pressure enclosures create a dust-free work area of better than 100 ppm for sensitive samples or instruments. Units protect samples from contamination with Class 100 or better clean air. Negative pressure units enclose materials and operations under negative pressure, preventing airborne contaminants from escaping into the work environment. Contaminated air is drawn through a variety of filters to remove pollutants and/or particulates and is recirculated as clean air back into the room. Filters are available for both vapors and particulates and can be combined. Custom ports and hinged doors accommodate particular applications or instruments. An optional UV sterilization lamp is available which destroys potentially contaminating DNA or RNA.